In this article, we evaluate ‘Professional traineeships for young people up to 30 years’, an active labour market policy measure implemented in the Czech Republic. Professional traineeships were one of the possibilities for suitable offer to young people within Youth Guarantee in the Czech Republic in 2014 and 2015. First, we conducted a process evaluation (document analysis and interviews) to uncover the design and implementation aspects of the program. Next, we followed the counterfactual impact evaluation approach towards the estimate of returns to unemployment (competing risk analysis) based on individual administration data from public employment services. We have found that professional traineeships were successful in attracting the interest of both young people and employers. Mainly young people with middle and high level education have entered the program. Most of them have been provided with on-the-job subsidies in the private sector. When considering the impact of the program on the unemployment of participants and a control group, it was shown that after two years, the measure was effective only for young people with long pre-program Employment Office registration. When we consider the reasons for leaving Employment Office registration, the measure seems to be more effective, since many young people in the control group left the Employment Office register in favour of options that were outside of the labour market.